package cc.wsyw126.java.nowcoder;

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

/**
 * Created by dp on 17/3/25.
 */
public class Prime {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n =scanner.nextInt();
        List<Integer> list = new ArrayList<>();


        for (int j = 2; j < 1000; j++) {
            if (m(j)) {
                list.add(j);
            }
        }

        int count =0;
        int low = 0, hight = list.size()-1;
        while (low <= hight) {
            int i = list.get(low) + list.get(hight);
            if (i == n) {
                System.out.println(list.get(low) + "," + list.get(hight));
                count++;
                low++;
                hight--;
            } else if (i<n) {
                low++;
            } else if (i>n) {
                hight--;
            }

        }
        System.out.println("count = " + count);
    }

    public static boolean m(int num) {

        for (int j = 2; j <= Math.sqrt(num); j++) {
            if (num % j == 0) {
                return false;
            }
        }

        return true;
    }

}